Reel-type lawn mowers mounted on tractor lift arms are well known in this art. It is common to have the tractor with a plurality of lift arms extending from the frame of the tractor and with the lift arm extending laterally and articularly supporting a reel type lawn mower. With that arrangement, the lawn mower is propelled by the tractor and can be moved up and down relative to the ground and also to a transport position, and the lift arm connection is such that the mower will also automatically ride up and down according to the undulations of the ground itself.
It is also common to have the reel particularly related to the lift arm itself so that the reel can be propelled in a castering action, that is, it can be pulled through its mowing function, and thus the reel will steer in accord with the moving direction of the tractor. Still further, it is common to have the reel interconnected with the tractor so that the reel can tilt from side to side and thereby also continue to track according to the grade of the ground over which it is moving.
In those prior arrangements, when the assembled tractor and reel mowers are making a turning action, one side of the reel tends to force itself into the turf while the other side will respond and rise above the turf. In that action, the grass is unevenly mowed, and the reel itself is forced downwardly into the turf throughout the turning action of the tractor and its reel. That is, the tractor lift arm extends laterally of the tractor, and thus laterally of the forward movement direction of the tractor, and it is that lateral lift arm that pushes laterally on the reel during the turning action, and that push creates the tendency for the reel to become angled or tilted, rather than parallel, relative to the ground line.
Accordingly, it is an object of this invention to reduce the tendency of the tractor-mounted reels to force downwardly onto the ground and thereby tend to ride up on one side of the reel when the assembled tractor and reel is making a turn. In the present invention, the aforementioned object is accomplished by providing a low connection point between the tractor lift arm and the reel and thereby the connection point it at a low elevation which does not cause the reel to unduly tip or move onto only one side in the course of the turning action. That is, the low connection provides a small moment arm from the tractor to the reel, and thus the reel tends to remain parallel with the ground on which it is riding and during the course of the turning action.
Still further, the present invention accomplishes the aforementioned and it does so with the particular connection at the forward location of the reel where that connection is in a caster arrangement, as desired, and the tractor and reel assembly still reduce the lateral force and moment effective between the tractor and the reel in the course of the turning or steering action mentioned. In that caster connection, the caster connection remains centered, relative to the reel, and substantially vertical, even through the rise and lowering of the reel in mowing over undulations on turf, and those features are also true during the lifting of the reel by the lift arm.
The arrangement is such that the reel is connected in relation to a horizontally disposed pivot axis at the end of the lift arm, and there is an offset link extending forwardly to the front vertical plane of the reel and at an elevation higher than the horizontal pivot elevation, all to achieve the aforementioned objectives.